This invention relates generally to poured concrete wall forms and, more particularly, to panels coupled together and used to construct the concrete wall form to produce a textured facade on the poured concrete wall.
Prefabricated, reusable panels are often used to construct a wall form for a poured concrete wall. Typically, two spaced opposed parallel sets of forms are erected and concrete is poured there between to form a wall. Each form is constructed of a number of adjacent interconnected panels. Form ties are used to maintain the spacing between the opposed forms constructed of the panels.
These panels are necessarily of relatively high strength, yet preferably they are compact and lightweight to effect savings in handling, transportation, and storage. Hence, the panels are commonly constructed at least in part of lightweight metal such as aluminum and have a reinforcing grid secured to the back side of the panel for providing the necessary strength to resist buckling under the weight of the poured concrete.
Typically, the grid on each panel has a marginal frame projecting rearwardly from the panel to include a flange along the spaced side edges of the panel. The flanges are adapted to be positioned in an abutting relationship with the flange of an adjacent panel to construct the concrete wall form. Holes in the flanges of the adjacent panels can be aligned to receive there through the shank of a pin or a bolt. The pin or bolt may pass through the ends of the ties and commonly are held in position by wedges which are driven through a slot in the shank of the pin or bolt. As the wedges are driven into the slot, the abutting flanges of the adjacent panels are drawn together. The pins and wedges offer a simple mechanism for effectively coupling the panels together.
When the concrete is poured between the spaced forms and assembled panels, the hydrostatic forces generated by the poured concrete tend to spread the opposed forms apart, but these outward or spreading forces are held in check by the form ties. In addition, the concrete expands as it sets creating greater spreading forces on the panels. The pin joining the adjacent panels together is subject to significant pulling forces by the form tie and an opposed force by the frame or rail on the panel.
Recently, such panels are commonly embossed with various designs to produce a decorative facade on the concrete wall formed by the panels. Thus, panels are available having a bat and board pattern to resemble the exterior walls of a conventional frame house, a ribbed pattern to resemble aluminum sliding or the like, and a smooth brick pattern to resemble brickwork construction. Examples of such wall form panels are shown in U.S. Pat. Nos. 1,776,999; 3,307,822; 3,549,115; and 4,407,480, each of which is hereby incorporated by reference in its entirety.
Panels which include an embossed or otherwise formed design to produce a decorative facade on the concrete wall optimally should produce a concrete wall facade as realistic as possible. In many known concrete wall form panels having a textured brick or other pattern, the pattern design is marred with blemishes or other marks inconsistent with the desired appearance. For example, the reinforcing grid or frame on the back surface of each panel is often spot welded to the back face of the embossed or textured face sheet of the panel. The spot welding naturally being produced at high temperatures produces a pock mark on the embossed surface of the panel. Such pock marks are typically inconsistent with the embossed pattern and produce a corresponding blemish or mark on the facade of the poured concrete wall. Obviously, such pock marks detract from the aesthetic appeal of the decorative facade on the concrete wall formed by such panels.
Notwithstanding the problems of producing realistic and aesthetic designs as discussed above, an additional problem common to all of the panel sections having a masonry type pattern embossed therein is that of damage to the panel and particularly the vertical marginal borders of the panels. In this regard, it is absolutely critical that these vertical marginal borders maintain their initial configuration inasmuch as the shape of the marginal borders influences the continuity in a wall formed by a plurality of form sections arranged side by side. For example, when the embossed pattern resembles smooth brickwork in an English cross-bond (joints between stretchers in one course positioned mid-length of stretchers in adjacent courses) the vertical edges of each panel traverse the pattern in such a manner as to present “half-bricks” in alternating courses along the vertical marginal borders of the sections. Thus, when sections so constructed are arranged side by side it is extremely important that the respective marginal borders match up exactly with their “half-bricks” precisely aligned to present a continuous full brick and hence, maintain the continuity of the brickwork pattern. However, in practice it has been found that panel sections having a brickwork pattern as previously described often become deformed along the vertical marginal borders thereof after only a few uses such that subsequent use of the form results in an unsightly discontinuous facade on the poured concrete wall produced by the section.
An additional problem with known panels of this type is the tendency for the panels to accumulate concrete. By their very nature, panels of this type have an irregular and non-planar face sheet. The configuration of the face sheet presents many openings, pockets, channels or grooves along the marginal edges of the face sheet adjacent the grid or flanges on the back face of the panel. When such panels are used to construct a poured concrete wall, the fluid concrete often finds its way into the openings, pockets, channels or grooves between the face sheet and the grid or flanges. When that concrete hardens or cures, it is permanently embedded in the panel and significantly increases the weight of the panel. Moreover, such embedded concrete often promotes separation or peeling of the face sheet from the grid or flanges ultimately resulting in damage to the panel and requiring disposal of the equipment.
Accordingly, it is apparent that there is a need to provide a panel section having a textured pattern embossed therein that produces a blemish-free, realistic facade while maintaining the structurally robust, compact and lightweight characteristics desirable in such panels.